org.wicketstuff.poi.excel.TablesComponentAsXlsHandler.java Source code

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Here is the source code for org.wicketstuff.poi.excel.TablesComponentAsXlsHandler.java

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/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.wicketstuff.poi.excel;

import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.Workbook;
import org.apache.wicket.Component;
import org.apache.wicket.markup.html.link.Link;
import org.apache.wicket.markup.html.navigation.paging.IPageable;
import org.apache.wicket.request.IRequestCycle;
import org.apache.wicket.request.IRequestHandler;
import org.apache.wicket.request.resource.ContentDisposition;
import org.apache.wicket.request.resource.IResource;
import org.apache.wicket.request.resource.ResourceStreamResource;

/**
 * <p>
 *       Request handler that respond the specified table components as a XLS file.
 * </p>
 * <p>
 *       A possible implementation of {@link Link} on click be:
 * </p>
 * <code>
 * public void onClick() {<br />
 * IRequestHandler handler = new TablesComponentAsXlsHandler("fileName.xls", table1, table2);<br />
 * RequestCycle.get().scheduleRequestHandlerAfterCurrent(handler);<br />
 * }
 * </code>
 *
 * @author reiern70
 */
public class TablesComponentAsXlsHandler implements IRequestHandler {
    private Component[] tableComponents;
    private String filename;
    private CellExporter cellExporter = new GeneralPurposeExporter();
    private Workbook workbook;

    /**
     * @param tableComponent
     * @param filename
     */
    public TablesComponentAsXlsHandler(String filename, Component... tableComponents) {
        if (tableComponents == null) {
            throw new IllegalArgumentException("At least one table compont should be passed as argument!");
        }
        this.tableComponents = tableComponents;
        this.filename = filename;
    }

    public void respond(IRequestCycle requestCycle) {
        try {
            workbook = new HSSFWorkbook();
            int index = 0;
            for (Component tableComponent : tableComponents) {
                TableParser parser = new TableParser(newSheet(workbook, tableComponent, index++), cellExporter);
                if (tableComponent instanceof IPageable) {
                    IPageable pageable = (IPageable) tableComponent;
                    for (int i = 0; i < pageable.getPageCount(); i++) {
                        pageable.setCurrentPage(i);
                        parser.parse(tableComponent);
                    }
                } else {
                    parser.parse(tableComponent);
                }
            }
            XlsStream xlsStream = new XlsStream(workbook);
            ResourceStreamResource resource = new ResourceStreamResource(xlsStream);
            resource.setFileName(filename);
            resource.setContentDisposition(ContentDisposition.ATTACHMENT);
            IResource.Attributes a = new IResource.Attributes(requestCycle.getRequest(),
                    requestCycle.getResponse());
            resource.respond(a);
        } catch (Exception e) {
            throw new RuntimeException("Error while generating a xls file to table component", e);
        }
    }

    public void detach(IRequestCycle requestCycle) {
        tableComponents = null;
    }

    /**
     * Create the sheet in where component table data will be set
     *
     * @return a new {@link Sheet} to receive the table component data
     */
    protected Sheet newSheet(Workbook workbook, Component component, int index) {
        return workbook.createSheet("Worksheet " + component.getId());
    }

    /**
     * Set the exporter strategy to be used by this handler. The default is
     * {@link GeneralPurposeExporter}
     *
     * @see CellExporter
     * @param cellExporter
     */
    public void setCellExporter(CellExporter cellExporter) {
        this.cellExporter = cellExporter;
    }

}